High Energy X-ray Diffraction with Crystal Plasticity Modeling

National Laboratory: 
Pacific Northwest National Laboratory
Characterization Class: 
Microscopy
Computational Tools Class: 
Materials Processing
Description: 

High Energy X-ray Diffraction with Crystal Plasticity Modeling, or HEXRD-CP, is a computational tool for interpreting high-energy x-ray diffraction results and characterizing individual phase properties, including critical stress and hardening parameters of dislocation slip systems. While HEXRD is a volumetric measurement technique that can be used to determine residual stresses, volume fraction, and textures of individual phases, it also can obtain the lattice distortions when used in combination with in situ tensile tests. A procedure using crystal plasticity modeling, including elastic plastic self-consistent scheme or finite element, has been established that can obtain individual phase properties, such as the critical stress and hardening parameters of existing dislocation slip systems.

Capability Bounds: 

The resulting phase characterizations obtained from HEXRD-CP can be used for advanced models that predict forming behavior and performance, such as fatigue and fracture failure during service, etc.

Unique Aspects: 

The HEXRD-CP procedure can obtain individual phase properties, which are especially difficult to directly measure.

Single Point of Contact: 

Name: Xiaohua Hu
Email: xiaohua.hu@pnnl.gov
Phone: 509-375-6681

References: 
  1. Hu, X. H., Choi, K. S., Sun, X., Ren, Y., & Wang, Y. D. (2015). Determining individual phase flow properties in a Quench and Partitioning steel with in-situ high energy X-ray diffraction and multi-phase elasto-plastic self-consistent method. Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science in revision.
  2. Jia, N., Cong, Z. H., Sun, X., Cheng, S., Nie, Z. H., Ren, Y., Liaw, P. K., & Wang, Y. D. (2009). An in situ high-energy X-ray diffraction study of micromechanical behavior of multiple phases in advanced high-strength steels. Acta Materialia 57, 3965-3977.
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